1. Field of the Invention
The present invention relates to the field of removal of brass valves from water mains.
2. Prior Art
Directly tapped valves were and still are a method of drilling into a pressurized pipe to construct a branch line. The apparatus used for this installation was known as a direct tap tapping machine or tapping machine. The machine was connected directly onto the pipe to be tapped and then drilled and threaded. Without removing the machine, the boring bar of the machine was drawn back and the drill/thread die was removed and a corporation valve was connected in its place. The corporation valve was then directly screwed into the threaded opening in the pipe. Over the years, this method of tapping has been reduced and has been replaced by the use of a saddle to encompass the exterior of the pipe and create a seal against the pipe. The corporation valve is then screwed into the saddle. The newer drilling machines now connect to the corporation valves and drill through the valve and eliminate the need for drilling and die threading the pipe first.
Nowadays, various city municipalities and water management agencies are requiring the removal of older directly tapped corporation valves from the water mainline. To accomplish this, the water main must be shut down and partially drained and not under pressure to manually remove the corporation valve from the piping and a “full circle” repair clamp placed over the opening in the pipe to assure a leak proof seal. The water main must then be pressured back up and bacterially re-tested to assure the quality of the water.
Other methods of immediate solutions have been to encapsulate the corporation valve by leaving it screwed into the pipe and with the use of a modified, full circle repair clamp that has been modified with an exterior tubular capsule that fits over the valve. This method isolates the valve inside a protruding sealed apparatus.